442 
MR. HODGKINSON’S EXPERIMENTAL RESEARCHES 
Table VIII. — Hollow Cylinders rounded at the Ends. 
Results of Experiments on the Strength of Hollow Cylinders of Cast Iron (the Low 
Moor, No. 3.), the ends having hemispherical caps upon them, that the compress- 
ing force might act through the axis of the pillar. Length of cylinder, including 
caps on the ends, 7 feet 6§ inches. Plate XV. No. 7 , A, B, C, &c. 
No. of Experiment, j 
Description of Pillar, 
Deflection. 
Weight 
producing 
the de- 
flection. 
Breaking 
weight, or 
that with 
which it 
sunk. 
Value of x from for- 
mula 
W 
Remarks. 
D 3 ' 76 - d 3 ' 76 ' 
where W = the break- 
ing weight, and D, d 
the external and 
internal diameters. 
inches. 
inch. 
lbs. 
lbs. 
lbs. 
1. 
Hollow uniform cylinder. 
•03 
2237 
With the weight 5585 lbs. the pillar sunk down, 
External diameter 1-78 
•07 
2813 
but was not allowed to bend so as to break. 
Internal diam. bymeasure J *21 
•11 
3317 
It was preserved in order that an experiment 
Internal diameter by cal- 1 
•16 
3821 
might be made upon it in another way. When 
culation j 
•20 
4325 
unloaded it became nearly straight, and was 
•32 
4829 
5585 
834-37 
easilyrendered so. The same plan was adopted 
Mean... 1*21 
•49 
5333 
with several otherpillars,as it was found that, 
Weight of cylinder, 7 ft. 6f inches 
by using care, this experiment might be made 
long, 31 lbs. 
with little injury to the pillar. The weight of 
the pillars, as set down, and the values of x , as 
calculated, are for a length of 7 ft. 6f inches, 
though the pillars were two inches shorter. 
2. 
Hollow uniform cylinder. 
•02 
2141 
This pillar sunk with the weight 5711 lbs. ; but 
External diameter 1‘74 
•03 
2813 
was prevented from breaking, as before, in 
Internal diam. by measure 1’20 
•05 
3317 
order that another experiment might be made 
Internal diameter by cal- 1 . . „ , 
•07 
3821 
upon it. When unloaded it had taken a per- 
culation J 1 ' 174 
•13 
4325 
manent set of '07 inch; but it had been found 
•20 
4829 
by the previous experiments that pillars 
Mean... 1-87 
•36 
5333 
slightly bent might be rendered straight, and 
Weight of cylinder, 7 ft. 6f inches 
•48 
5585 
5711 
933-13 
used again with little damage, as was done 
long, 30J lbs. 
with the preceding one. 
3. 
Hollow uniform cylinder. 
•04 
2237 
It sunk down as usual, and when unloaded had 
External diameter 2 - 01 
•13 
4829 
taken a permanent set of one-tenth of an 
Internal diam. by measure 1-40 
•21 
5837 
inch. Thickness of metal at place of frac- 
Internal diameter by cal- 1 . , „ 
•31 
6845 
ture varied on the opposite sides as 19 : 42. 
culation j d 
•58 
7853 
This pillar was not reduced near the ends, j 
•75 
8105 
8357 
826-20 
\ 
Mean... 1-415 
Weight of cylinder, 7 ft. 6f inches 
long, 364 lbs. 
4. 
Hollow uniform cylinder. 
•24 
11169 
It sunk down as usual, but was prevented from 
External diameter 2-33 
•30 
11953 
bending so as to break : it was broken after- 
Internal diam. bymeasure 1-70 
•37 
12737 
wards. The core did not pass through the 
Internal diameter by cal- 1 - 
•46 
13521 
centre: the thicknesses of the opposite suHs 
culation J ‘ 0 
•61 
14305 
at the place of fracture were as 1 : 4 nearly ; 
•72 
14697 
15089 
903-28 
the thinner side having been the compressed 
Mean... 1-70 
one, as was often the case. 
Weight of pillar, length as above, 
46^ lbs. 
5. 
Hollow uniform cylinder. 
•01 
2237 
It sunk as usual, but was prevented from break- 
External diameter 2-23 
•06 
4325 
ing. This pillar was not reduced at the ends. 
Internal diam. by measure 1 -53 
•12 
6341 
Internal diameter by cal- 1 , , _ 
•22 
8357 
culation J 1 ' 50 
•28 
9365 
•37 
1 0373 
Mean... 1-54 
•45 
10877 
Weight of pillar 47 lbs., length as 
•55 
11381 
above. 
•69 
12137 
12389 
808-21 
6. 
Hollow uniform cylinder. 
•015 
2141 
External diameter 2-24 
•02 
7101 
Internal diam. by measure 1-71 
direction 
Internal diameter by cal- 1 . 
altered. 
culation J 
•04 
8165 
•34 
12445 
Mean... 1-735 
•38 
12669 
13341 
1041-7 
Weight of pillar 34 \ lbs. 
